Process of manufacturing 2, 2, 4-trimethyl-3-penten-1-ol and 2, 2, 4-trimethyl-pentanol



PROCESS OF MANUFACTURING 2,2,4-TRIMETH- gkggENTEN-l-OL AND 2,2,4-TRIMETHYL-PEN- Filed July 23, 1958, Ser. No. 750,288

2 Claims. (Cl. 260-638) No Drawing.

This invention relates to a new compound, 2,2,4- trimethyl-3-penten-l-ol, and to a process of making it. It also relates to a process of making 2,2,4-trimethylpentanol. It also relates to esters of 2,2,4-trimethylpenten-l-ol which are new compounds.

We have found that 2,2,4-trimethyl-3-penten-1-01 can be prepared by pyrolysis of a lower aliphatic monocarboxylic acid diester of 2,2,4-trimethyl-1,3-pentanediol, followed by hydrolysis of the product. The esters of 2,2,4-trimethyl-1,3-pentanediol can be prepared by esterification of the diol by ordinary methods, such as are shown, for example, in US. Patent 2,625,563.

Pyrolysis of the diesters of 2,2,4-trimethyl-1,3-pentanediol is carried out at temperatures in the range of 300- 600 C., using contact times varying from 0.01 second to 10 seconds. The pyrolysis can he carried out in an empty tube or over suitable refractory materials such as Pyrex chips, alundum, zirconium oxide, titanium oxide, or other inert material.

Example 1.-466 grams of 2,2,4-trimethy1-1,3-pentanediol diacetate was pyrolyzed over porcelain Berl saddles using a contact time of 1.5 seconds at 500 C. Distillation of the product on a 30-plate column. at 10 to 1 reflux showed a 48% conversion to 2,2,4-trimethyl-3-penten-l-ol acetate, boiling point 187 C. The yield, based on the 2,2,4-trimethyl-1,3-pentanediol diacetate consumed, was 89%. Saponir'ication of this 2,2,4-trimethyl-3-penten- 1-01 acetate gave a quantitative yield of 2,2,4-trimethyl- 3-penten-l-ol, boiling point 170 C. Percent hydroxyl (phthalate) 100.6; Calc. C=75, H=12.5, =12.5; Found C=75.02, H=12.46, 0:12.52. Unsaturation was 99.86% as trimethylpentenol. Hydrogenation over Raney nickel gave 2,2,4-trimethylpentanol, B.P. 166 C. Oxidation gave acetone and dimethylmalonic acid.

CH: 00 C.OH:

7 nited States Patent 0 Ha acetic acid 6 2,2,4-m'imethyl-8-penten-wl acetate 1 NeOH CH: CH3 CH1. =CH--CHI-OH HI azetrlmethyl-epenten-l-ol 2,2,4-trimethyl-1-pentanol Example 2.572 grams of 2,2,4-trimethyl-1,3-pentanediol diisobutyrate was pyrolyzed over Pyrex chips at 500 C., employing a l-second contact time. Distillation of the product on a 30-plate column at 10 to 1 reflux ratio gave 165 g. of isobutyric acid and 327 g. of 2,2,4-trimethy1-3-penten-1-ol isobutyrate, boiling point 212 C. The remainder of the 2,2,4-trimethyl-1,3-pentanediol diisobutyrate was recovered unchanged. Saponification of the 2,2,4-trimethyl-3-pentene-1-ol acetate isobutyrate gave 2,2,4-trimethyl-3-pentene-l-ol.

The carboxylic acid esters of 2,2,4-trimethyl-l-pentanol are useful as oxidation-resistant plasticizers.

What we claim as our invention and desire to be accured by Letters Patent of the United States is:

1. A process of preparing 2,2,4-trimethyl-3-penteml- 01 which comprises pyrolyzing a lower aliphatic monocarboxylic acid diester of 2,2,4-trimethyl-L3-pentanediol and hydrolyzing the resulting lower aliphatic monocarboxylic acid ester of 2,2,4-trimethy1-3-penten-l-ol.

2. A process of preparing 2,2,4-trimethyl-pentanol which comprises pyrolyzing a lower aliphatic monocar boxylic acid diester of 2,2,4-trimethyl-1,3-pentanediol, hy-

drolyzing the resulting lower aliphatic monocarboxylic acid ester of 2,2,4-trimethy1-3-penten-l-ol to 2,2,4-trimethyl-3-penten-1-ol, and hydrogenating the 2,2,4-trimethyl-3-penten-l-ol.

References Cited in the file of this patent UNITED STATES PATENTS 2,042,221 Groll et a1. May 26, 1936 2,246,285 Arundale et a1 June 17, 1941 2,251,983 Chitwood Aug. 12, 1941 OTHER REFERENCES Courtot: Bull. Soc. Chem., France (3) 35, 222 (1906). Van Aerde: Rec. Trav. Chem. 28, 171-179 (1909).

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 2,941,011 June 14 1960 Hugh Jo I-lagenracyer 313, et a1,

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, line 29 strike out "acetate.

Signed and sealed this 6th day of December 1960,

(SEAL) Attest:

KARL Hr AXLINE ROBERT C. WATSGN Attesting Officer Commissioner of Patents 

1. A PROCESS OF PREPARING 2,2,4-TRIMETHYL-3-PENTEN-1OL WHICH COMPRISES PYROLYZING A LOWER ALIPHATIC MONOCARBOXYLIC ACID DIESTER OF 2,2,4-TRIMETHYL-1,3-PENTANEDIOL AND HYDROLYZING THE RESULTING LOWER ALIPHATIC MONOCARBOXYLIC ACID ESTER OF 2,.2,4-TRIMETHYL-3-PENTEN-1-OL. 